Induction-coil structure



A. A. KENT.

INDUCTION COI\L STRUCTURE. APPLlb/nlou FILED luLY 9. 1921.

1,391,256, Patentedseptfzo, 1921.

2 SHEETS-SHEET l.

A IllllllllllIlll/llll/111111 ll/ l INVENTOR BY M S6612/ 'MMM A. A.KENT.-

INDUCTION COIL STRUCTURE.

APPLICATION mso JULY 9, 1921.

Pawnwdsept. 20 1921.

2 SHEETS-SHEET 2.

//////////////, f/l/////// f/ l a l INVEN/ y ARTHUR 'ATWATEE KENT, orARDMOE'E, PENNsYLvANIAgAssIGNoE To ATWATER KENT MANUEACTUEING'COMPANX,or PHILADELPHIA, PENNSYLVANIA, A con,

PORATION vrF PENNSYLVANIA.

INnUcTIoN-COILFSTEUCTUEE.

, Be itr .known thatI, ARTHUR ATWATEE KENT, a citizen of thefkUnitedStates, resid-fv ing in Ardmore, county of Montgomery and State ofkPennsylvania, have invented certain new' and useful improvements inInduction-Coil Structures, of which the fol-4 lowing is a specification.

My'y invention relates to indu'ctioncoils and particularly to' thosecoils that. are:l yadapted forusein the sparking systemslof internalcombustion engines.

The objects of-thisxinvention, lare to piro-y vide` an induction coilthat `is entirely 1n-- closed and protected, rand isV also easily andycheaply constructed landfassernbled; t'o pro= videa casing therefor,which is strong, stiff,3

durable and light inweight; `to provide the induction coil proper with asuitable resist-71, ance to prevent heating of the coilfwhenrthe primarycircuit is rclosed for relatively long@ periods, to provide ahousingforlthe resistance ,and to make afcoil which is. attractive,' Land simple 1nappearance.

Other objects'of my invention will appear in the yspecification andclaims below.

Referringto the drawing forming apart of this .specificationand in whichthe same` reference characters arev used to designate the same partsthroughout lthe views Figure 1 1s a vertical section of an inductioncoilemobdying my invention,the primary and.

secondar windings not being shown in secs tion; an Fig. 2 is aplan viewvof the device shown in Fig. 1,-.with the upper outerv capy or.y

cover removed.

Fig. 3 is a yview,`siinilar to Fig. ,1, show# ing a modifiedconstruction, and Fig. '4 is a plan view of the lSame with theouter capre'- moved.k

Figs. I 5,kr c,y 7 andl s show further modified forms of the inventionv,i

' The induction coil proper consists of' two;

windings, as usual, 'a .primary winding or coil l1 and a secondarywinding or 60H2. v surrounding the primary OOL .The Casing thereforpreferably consists of insulating material in `the form of a tube 3 ofcardboard, liber, or other 'thick paper. Into one.'y

end of said tube 3 a disk- 4, preferably of sheet metal, having anintegral peripheral ftaching, thereto a lead wire "ondary circuit.

"spificatibiI-or Leitersratent. Y kPatented Sept. 20, 17921.

` Continuationr of application` Serial No. 131,749, led November 16,

v 1921. LVSerial No. 483,423.

cylindrical flange 5, slightly larger than the diameter of the interiorof the tube 3, is

forced under considerable pressure with af `flange extending tightlyinto the tube 3, and

the disk 4 substantiall flush with th the tube 3. y' e end of Over thatend of the tube 3 into whichfy the flanged disk 4 has been so inserted,a sheet metal ring 6 is next forced, under pressure,l said ringG beingprovided with an integral cylindrical Hange 7 of they same diameter as,or vslightly smaller thanrthev outside diameter of the tube 3, and whichtightly fits over the-exterior surface of the 191,6. This applicationleduly 9,M

end ofthe tube 3. .In this manner the cylindllCill flanges 5 and7 of thedisk 4 and ring :6, respectively, tightly clamp and hold the.

tube 3 between themy yand the said flanges alsogreatly. stiffenthesaiddisk 4, ring 6 Vand .tube 3. Y p A disk 8 of cardboard, fiber orother ma'.-

l terial, which-is preferably non-magnetic and ra non-conductor ofelectricity, is thenplaced y within-the tubev3 resting on the disk 4 andthe induction coil, comprising thepriinary fcoil 1 and secondary coil 2,is placed centrallyy in the tube 3 resting on the disk 8 andv fwith `aterminal 9 ofthe secondary coil 2 'connected to the primary lead 10,through which 1t may be grounded or otherwise suitably connectedincircuit I c The other terminal 11 of the secondary coil is attached toa ybinding post 12 passing through 1 and tightly fitting into a holethroughthe tube 3. The binding'post may be ,providedfwith a flanged head13 and electrical contact. The outer end of said -binding'stud 12 may beprovided witli screw" 'threads 15 over which'the knurled nut 16l may be`threaded for the purpose' of at- Gneterniin'al 1S of the'lprimarycoil"v is 17 of the secy y'betweenfsaid-head'l and al Inetalwvasher 14,the said terminal 11v may be heldingood preferably connected to the leadl0 and i may be thus grounded. The other tlead19 is Apreferably leftextending upwardly from -th'eprimary coil 1.

ico

The tube 3 with theinduction coil therein is then preferably filled withmelted'wax, i'

paraffin, or some similar insulating material 20 to nearly the top ofthe tube 3 so that the induction coil is completely inclosed and coveredthereby and the war; is allowed to cool and solidify, the terminal 19 ofthe primary coil extending above the top surface of the wax or paraffin.

The terminal 19 of the primary coil is now passed through an opening 21in an inner diaphragm, cover or cap 22, preferably of sheet metal, andcomprisinga disk-like top 23, and a cylindrical flange 24, the outerdiameter of which flange is of the same or slightly larger diameter thanthe inner diameter of the end of the Vtop of the tube 3. The liange disk22 is then forced under pressure tightly into the tube 3 until the topend of the tube and the top 23 of the inner cover 22 are substantiallyfiush.

On the top of the inner cover 23 is secured a preferably rectangularsheet or plate of mica 25 around which is wrapped in spiral separatedcoils a length of preferably nickel wire to form a resistance coil 26.'Ihis mica plate 25 may be secured to the top 23 of the inner cover 22by a rivet 27 passing through said mica plate 25, through a bushing 28,which may be of insulating material,-

and through an insulating washer 29 and a metal washer 30 on the other0r inner side of the inner cover 22. One end of said resistance coil 26is secured in any suitable manner to the end of the lead 19 passingthrough the opening 21 of the inner cap 22.

Over the upper end of the tube 3, and inclosing the resistance coilmounted on the top of the inner cover or cap 22 is an outer metal coveror cap 31, provided with a cylindrical flange 32, the inner diameter ofwhich is slightly less than the outer diameter of the tube 3. This utercap or cover 31 is preferably provided at its center with a brass stud33, the top end of which is passed through a suitable opening in the topof the outer cap or cover 31 and is headed over by pressure and thusfirmly substantially riveted thereto. This brass stud or bushing 33 ispreferably provided inside of the cap or cover 31 with a groove 34 intowhich one end of the piece of copper wire 35 is wrapped. Preferably thiswire 35 is wrapped around the said stud or bushing 33 when the bushingis inserted through the cap 31 and then the said stud 33 is compressedbetween dies under high pressure to head over the top of the stud orbushing 33 and secure it thus to the cover, and to close the groove 3 4upon the wire 35 to firmly unite the said wire 35 to the stud or bushing33.

The stud or bushing 33 is preferably provided with a tapped hole 36 forthe reception of a binding screw 37 to which a lead 38, adapted' to beattached to the interrupting mechanism may be attached.

The other end of the resistance coil 26 is connected to the copper wire35 and then the outer cap or cover 31 is forced under pressure over theouter surface of the upper end of the tube or cylinder 3. In this mannerthe tube 3 is made stiff and rigid by being clamped tightly between theflange of the inner cap or cover 22 and the flange of the outer cap orcover' 31.

The cap or cover 31 is preferably provided with a plurality of holes 39to permit of the free circulation of air over the resistancecoil 26,thus inclosed within a chamber between the inner and outer caps orcovers 22 and 31, respectively.

In Fig. 3 is shown a modified form of induction coil in which the lead19 is attached directly to the metal cap 22 by a bolt 40 and metalwasher 41, and the adjacent end of a spiral resistance coil 26,preferably of nickel wire, is clamped by a nut 42 on said bolt 40,between a metal washer 43 and the top of Vthe cover 22. The other end ofthe coil 26 is, however, clamped, between insulating washers 44 and 45surrounding the ends of an insulating bushing 46 passing through thecover 22 and through which a bolt 47 passes. A nut 48 on the end of thebolt 47 holds the end of the resistance coil firmly 0n but insulatedfrom the inner cap 22. In this case the lead 38 may extend through abushing 49 of insulating material through the outer cap 31 and is heldclamped in electrical engagement with the end of the resistance coil 26by the bolt 47.

In Fig. 5 is shown a still further modified form of the device. In itthe inner cap 22 is provided with an insulating washer or bushing 50through which the lead Y19 passes. In this manner the inner cap 22 iscompletely insulated from the lead 19, from the induction coil and isalso insulated from the resistance coil 26.

In Fig. 6 is a further modified form. The lead 19 is in this instancesoldered directly to the under side of the inner cap 22 and one end ofthe resistance coil 26 is soldered to the top of the cap or cover 22. Inthis manner the inner cap is made a part of the conductor of the primarycircuit and the passing of the lead 19 through the inner cap 22 isobviated.

Sometimes it is; desirable to lead the ground wire 10 through the outercap 31 and this arrangement is shown in Fig. 7 in which the inner cover22 is provided with an insulating bushing 51 and the outer cap 31isprovided with an insulating bushing 52 through which the lead 10 isconducted to the outside of the casing. In this modified form of theinvention the resistance coil 26 and the lead 19 are shown as soldered,respectively, to theopposite sides of the inner cap 22, as in Fig. 6.

When it is desired so to do the resistance of the tube 3`throughbushingsl and`55,

res ectively. f f

`he induction vcoils abovek described are particularly yadapted for yusein normally closed sparking Vcircuits of internal combustion engines,thatfis to say, in systems in Which the primary circuit is held normallyclosed`and the spark is caused by a current induced in the secondarycoil by breaking the primaryv circuit. Resistance 26 serves to vcontrolor limit 'the current in ther primary Winding, rof the indu'ctioncoil.

By tightly forcing the aanged disk 4 wahin the ring 6 overthe outside ofthe tube 3, and the flanged disk 23l within and the outer cover or :ca31 over ythe outside ofthe tube 3, the who ei tube or casing V3 ismadevery stiff` andrigidf The parts are permanently unitedtogetherwithout cement, screws, or any other fasteningk devices, for.the friction between the tube and vrthe/.said parts serves to holdtheparts rigidly and permanently together, making otherfastening means un`necessary. f l Y e While vI yhavefreferredto l'thefuse of solidifiedoncongealed paraiiin in'whichthe coil is embedded and covered, any othersuitable insulating material may be substitutedk thereforasfoccasion'might make expedient.

The inner heads4 and 22, the ring 6 and the outer cap 31 are preferablystamped from sheet metalandtheir flanges snugly lit the Ladjacentsurfacesfof'said tube 3 into engagement` with which' they are forcedunderconsiderable pressure. e

This application isa substitute for or continuation yof application Ser.No.f131,7.49, filed November 16,1916. n

What I claim is: A y

l. Induction coil structure comprising an inclosingcasin'g, anyinduction coil therein, a cap on one end of said casing, and aresistance element connected in series with the primaryv ofsaidinduction coildisposed between said cap and said inductioncoilg 2.Induction coil structure comprising an inclosingk casing,an inductioncoil i. therein,

a perforated r,cap on one vend ofr said casing,A

anda .resistance elementconnected' with the primary of said inductioncoil disposed between said `cap rand said induction coil.

3. Induction coil'structure comprising an inclosing casing, anyinductioncoil therein, a cap on one end of said y casing,a resistanceelement series with the primary of said induction coil disposedibetweensaid cap and saidinduction coil, and a primary ter-` minal carried bysaid cap.

4. Induction coil structure 'comprising an,V inclosing casing, aninduction coil therein, a cap on one end of said casing, a resistanceelement connected With the primary of said induction coil disposedbetween said `cap and saidinduction-coil, and a primary ter-y minalcarried by said cap and connected to said resistancey element 5.Induction coil structure comprising an inclosing casing, an inductioncoil therein, alead common to the primaryl and secondary 4coils of saidinduction coil extendingxthrough the side of saidl casing, a connectionto the otherterminal of said secondary extending through the side ofsaid casing, a vcap on said casing, a resistancel element disposedbetween said cap and said induction coil, la termina-l carried by saidcap, and a connection from the other terminal of said primary coil tosaid terminal i on said vcap through said resistanceelement.

6. Induction coil structure comprisingan inclosing casing, aninductioncoil therein, a lead connected'with one terminal of the primarycoil extending through the side of said casing, aconnection to aterminal of the secondary `coil extending throughthe sidefof saidcasing, a cap on said casing, a resistance element disposed between saidcap andsaid induction coil, a terminal carried by said cap, and aconnection from the e other terminal of said -primary coilto said v100terminal on saidk cap through said resistance element. n i

7. yInductionfcoil structure comprising an inclosingcasing of insulatingmaterial, an

induction coil therein, metallic caps engag-* ing said casing internallyand externally and .insulated from each other by said casing,

and insulated from each otherpby said cask ing, a resistance yelementinthe space between said caps, and a terminal carried by the externalcap `and connected with they prie,v mary ofsaidinduction coil throughsaid resistance element.M K

9. Induction vcoil structure comprising an inclosing casing, aninduction coil therein,

a cap` on said casing, a metallic member between said cap and saidinduction coil forming an end closure for said casing, a support ofinsulating material carried by said metalf lic member and disposedbetween it and said y cap, and a resistance` element disposed upon saidinsulatingsupport and connected With the primary of said induction coil.

10. Induction coil structure comprising an inclosing casing, aninduction coil therein, a cap on said casing, a metallic member betweensaid cap and said induction coil forming an end closure for said casing,a support of insulating material carried by said metallic member anddisposed between it and said cap, a resistance elementV disposed uponsaid insulating support, a terminal carried by said cap, and aconnection from said terminal to the primary of said induction coilthrough said resistance element.

11. Induction coil structure comprising an inclosing casing, aninduction coil therein, a cap on said casing, a. metallic member betweensaid cap and said induction coil forming an end closure for said casing,a conducting member carried by and insulated from said metallic member,a support of insulating material held by said conducting' member anddisposed between said cap and said'metallic member, and a resistanceelement carried by said supporting` member and connected with theprimary of said induction coil.

1Q. Induction coil structure comprising an inclosing casing, aninduction coil therein, a cap on said casing', a metallic member betweensaid cap and said induction coil forming an end closure for said casing,a conducting` member carried by and insulated from said metallic member,a support of insulating material held by said conducting member anddisposed between said cap and said metallic member, a resistance elementcarried by said supporting member, a terminal carried by said cap, and aconnection from said terminal to the primary of said induction coilthrough said resistance element.

13. Induction coil structure comprising an inclosing casing having twochambers, one of said chambers containing an induction coil, and theother of said chambers containing' a resistance element for limiting theflow of current to said induction coil.

lll. Induction coil structure, for use in an ignition system of a kmotorvehicle, comprising an inclosing` casing having two chambers, one ofsaid chambers containing an induction coil, and the other of saidchambers containing a resistance element for limiting' the flow ofcurrent to said induction coil.

15. Induction coil structure comprising an inclosing casing having twochambers, one of said chambers containing an induction coil, and theother of said chambers containing means for limiting the flow of currentto said induction coil.

16. An induction coil unit comprising the combination of a casingcomprising a cylindrical tube 0f insulating' material, inner sheet metalheads each having a cylindrical flange forced into opposite ends,respectively, of said tube, with the outer surface of said flanges intight frictional engagement with the interior surface of the ends ofsaid tube, and outer sheet metal end members each having a cylindricalflange forced over the ends, respectively, of said tubes with theinterior surface of said flanges in tight frictiona-l engagement withthe exterior surface of the ends of said tube, an induction coil withinsaid casing, and insulating material filling the space between said coiland said casingand inclosing said coil. 1T. An induction coil unitcomprising the combination of a cylindrical tube of insulating material,a disk of sheet metal having a cylindrical fiange forced into one end ofsaid tube with the outer surface of said flange in tight frictionalengagement with the inner surface of the end of said tube, an outermember having a cylindrical flange forced over said end of said tubewith the inner surface of said flange in tight frictional engagementwith theouter surface of said tube, a member of insulating materialwithin said tube and positioned on the inner surface of said fiangeddisk, and an induction coil in said tube resting on said sheet.

18. An induction coil unit comprising the combination of a cylindricaltube of insulatlindrical fiange tightly forced into one end of saidtube, an outer member having a cylindrical flange tightly forced oversaid end of said tube, said disk and said outer member being fixedlyretained in position by the friction between them and said tube, aninduction coil in said tube embedded in con- `sealed insulatingmaterial, poured in a fluid condition into the space between said coiland said tube, a metal disk having a cylindrical flange tightlyrforcedinto the other end of said tube, and an outer cap of sheet metal havinga cylindrical flange forced over said last mentioned end of said tube,said last mentioned-metal disk and said outer cap being permanentlyretained on said tube by the frictional engagement between them and saidtube.

19. An induction coil unit comprising the combination of a cylindricaltube, a head forced into one end of said tube having its outer surfaceflush with the end of said tube and a ring member forced over the outersurface of said end of said tube, an induction coil within said tube andsurrounded by insulating material, a head forced into the other end ofsaid tube with its outer surface substantially flush with the other endof said tube and a cap forced over the said last mentioned end of saidtube, said heads,

cap and ring being retained permanently to said tube by friction betweenthem and said tube, and serving to make said paper tube stiff and rigid.

20. An induction coil unit comprising the combination of an insulatingtube, fianged ingmaterial, a sheet metal disk having a cyy flange tightlsaid tube an heads'of sheet metal tightly forced into opposite ends ofsaid tube, a flanged ring `of rigid material tightly "forced over theeX- terior surface of one end of said tube, ajcap of sheet metalprovided withv a cylindrical forced over the other end. of roviding achamber between saidcap and t e `head forced into that end of said tube,an induction coil contained within'saidtube, a binding post secured tosaid tube intermediate the ends thereof, a terminal of the secondarywinding of the said coil being attached to said binding ost, and aterminal of the primary windin of saidinduction coil passing throughsald ca and the head in the same end of said tu 21. An induction coilunit comprising the ycombination of a tube, an induction coil mountedytherein, a Vflanged metal cap eX- tending over` the outer surface ofsaid end'of said tube and providing a chamber between said cap and saidinduction coil, and aresistance mounted in saidV chamberand connected inseries withthe primary winding of said induction coil.`

22. An induction coil unit comprising the combination of la tube ofinsulating material closed at one end, an induction coil within e videdwith openin said tube, a diaphragm inf-the end of said tube, avcap'extendingover the outer surface of said end of said tubefand providinga chamber between said cap and said diaphragm, and a resistance mountedwithin said chamber in series with the primary winding of said coil,said cap being profor circulation of air throu h said cham er. y t

23. n an ignition sparking means for an i ition system for use in amotor vehicle, t ey combination of anvinduction coilhermetica'llyfembedded in insulating material, a cylindrical tube ofinsulating material surrounding said embedded coil, flanged metal diskswith theflanges thereof tightly forced Within the oppositevr ends ofsaid tube, a

l flanged ring with the flange thereof tightly forced over yone end ofsaid tube,`a flanged `cap with the flange thereof tightly forced saidcap are permanently and rigidly frictionally secured together, and aresistance coil connected -in the primary circuit of said induction coiland mounted upon one of said fianged'- disks between said fianged diskand said flanged cap.

24. Aunitary sparking device for ignition systems used in motorvehicles, comprising an induction coil hermetically embedded incongealed insulatinv material, a rigid tube of insulating materialsurrounding said embedded coil, circular flanged members tightly forcedwithin and over the ends of said tube for frictionally, ermanently andrigidly securing said mem ers to said tube, and a resistance connectedin the primary circuit of said induction coil inclosed in a space formedbetween two of said flanged members.

25. Aunitary ignition sparking device for use in an ignition s stem of amotor vehicle, comprising an in uction coil hermetically embedded incongealed insulating material, a tube of insulating material surroundingsaid coil, spaced end heads respectively in f prising the combination ofa tubular casing,

an induction coil therein, a diaphragm within and extending across saidcasing at one end of said induction coil, a cap on said casing s acedfrom said diaphragm to form a Vcham er, and a resistance disposed insaid chamber and connected. with the primary winding of said inductioncoil.

In testimony whereof I have hereunto affixed my signature :this 30th dayof June,

ARTHUR ATWATER KENT.

